EP0018211A1 - Spurverfolgungsanordnung für einen Sensor zur Wiedergewinnung von auf eine Informationsspur aufgezeichneten Signalen - Google Patents
Spurverfolgungsanordnung für einen Sensor zur Wiedergewinnung von auf eine Informationsspur aufgezeichneten Signalen Download PDFInfo
- Publication number
- EP0018211A1 EP0018211A1 EP80301240A EP80301240A EP0018211A1 EP 0018211 A1 EP0018211 A1 EP 0018211A1 EP 80301240 A EP80301240 A EP 80301240A EP 80301240 A EP80301240 A EP 80301240A EP 0018211 A1 EP0018211 A1 EP 0018211A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- diodes
- track
- array
- output
- tracking arrangement
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000003287 optical effect Effects 0.000 claims abstract description 8
- 239000004020 conductor Substances 0.000 claims description 15
- 230000005855 radiation Effects 0.000 claims 1
- 239000004065 semiconductor Substances 0.000 claims 1
- 238000009792 diffusion process Methods 0.000 description 7
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000002184 metal Substances 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B21/00—Head arrangements not specific to the method of recording or reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0901—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following only
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/1446—Devices controlled by radiation in a repetitive configuration
Definitions
- the present invention relates to tracking arrangements for optical or like sensing devices for signals on an information track for example a spiral track on a video disc or a complete memory.
- optical sensing of a spiral track - alternatively circular tracks - on the disc is accomplished by reflecting light off the surface of the disc. and onto a photo-optic sensor.
- One way of tracking in such an optical recorder is to move the photo-optic sensor radially inward as the disc rotates so the photo-optic sensor scans the entire disc.
- One problem with such a tracking and sensing system is that because of manufacturing tolerances and other problems the spiraling of the track is not uniform but has eccentricities. These eccentricities cause cross talk in the optically sensed data and also cause the skipping of certain sections of the track while repeating other sections of the track.
- a tracking arrangement comprises an array of sensor devices (18) arranged to be disposed transversely in relation to the track, a first set of alternate devices (18., 18. 2 ) in the array being capable of connection to a first output (20), and a second series of the intermediate devices (18 i-1 , 18 i+1 ) being capable of connection to a second output (22) means (26) responsive to a combination of the outputs to provide a first signal representative of the information on the track, and responsive to a second combination of the output to provide a second signal for controlling which pair of two adjacent devices (18) one from each series are coupled to the first and second outputs.
- the sensors may be photo-optical sensors fabricated in a string on a monolithic chip. Light from the desired portion of the track is initially focused onto two of the sensing devices in the string. The outputs of those two devices are summed together to produce the video output signal for the optical disc player and are also subtracted from one another to generate a differential output for tracking purposes.
- This differential output is a comparison of the magnitudes of the electrical outputs of the two devices and therefore is a measure of how much light is reaching each of the diodes, and therefore of the lateral position in relation to the track.
- a decoder responds by causing the particular adjacent devices which are receiving the light to be switched to the output to generate the video output signal and the difference signals.
- the devices are conveniently arranged so that the output terminals of each two adjacent devices are on opposite sides of the array. This makes it possible to have a high density of the diodes on the monolithic chip and thereby increase the resolution of photo-optic sensor.
- the decoder may include a switching mechanism which reverses the sensor device connections to the decoder as they switch during tracking.
- an array of sensor devices on a single chip comprises a common elongate anode conductor (72) and a number of cathode conductors (74a) spaced apart along the length of the anode conductor, each cathode conductor being an elongate strip extending away from the anode conductor, alternate strips extending to opposite sides.
- a disc 10 with a spiralling track 12 of digitally encoded information on it is illuminated by a light source 14.
- Light reflected off the encoded information in the track provided is more intense than that reflected off the guard bands between the turns of the track.
- This reflected light passes through a magnifying lens 16 and is focused on an array of diodes 18. There are 128 diodes in two sets of sixty four.
- the diodes of the array are arranged in a string. Electrical connections to adjacent diodes in the string are made to two different output lines 20 and 22 on opposite sides of the string.
- the diodes 18 are each coupled to one of the lines 20 or 22 through an enhancement mode field effect transistor (FET) 24. At any one time only two of the FET's are biased conductive to electrically connect one diode 18 . to line 20 and another diode 18 i+1 to line 22. These two diodes are adjacent to each other and have their outputs summed by the logic circuitry 26 to generate the video output signal V Out.
- FET enhancement mode field effect transistor
- the logic circuitry 26 not only provides the output signal for the video player but it also generates selection signals on decode lines 27 for the gates of the devices 24 that connect the two diodes 18 i and 18 i+1 to the lines 20 and 22. To this end the logic circuitry 26 generates an up or high level signal on two and only two decode lines 27 thereby biasing two FET's 24 on and provides down voltages on all the other decode lines 27 to maintain all the other FET's 24 biased off.
- the selection of the two diodes 18 is made on the basis of which two diodes in the array are in position to optically sense the desired portion of the spiralling track.
- the two diodes 18 i and 18 i+1 are optically centered over the Nth revolution of the track and electrically connected to the lines 20 and 22 respectively.
- the diodes 18 i and 18 i+1 would then be operating at point 30 of their output curves.
- neither diode 18 i or 18 i+1 is sensitive to light from adjacent tracks N-1 or N+l. If the spiral of the track were . true, movement of the sensor across the record by mechanical devices alone would be sufficient to maintain the diodes 18 i and 18 i+l in registration with the track as it spirals inwardly.
- the point at which light from the center track N hits the array of diodes can change from the center of diode 18 i to the center of diode 18 i+1 without picking up light from adjacent tracks N-1 and N+l with diode 18 i or 18 i+1 Larger drifts than this can result in picking up data from adjacent tracks and for this reason the diodes producing the two components of the output signal are changed with such larger drifts.
- the difference voltage VD between the two output voltages V i and V i+1 corresponding to the currents from the diodes 18 i and 18 i+1 is used to determine when changes in diodes are to be made.
- the diodes 18 i and 18 i+1 produce outputs which are identical so that the difference voltage VD is equal to zero.
- the one diode would produce a larger output signal than the other diode.
- the present invention makes use of this increase in the difference voltage to switch the exciting voltage on the gate of the devices 24 coupling the diodes 18 to the lines 20 and 22.
- the diodes 18 are spaced so that the operating spectras of the diodes are each as wide as the track or the guard band between the tracks,Therefore, the voltage difference VD will increase until either diode 18 i or 18 i+1 is optically centered over the track.
- VD max can then therefore be used to change the combination of diodes 18 used to produce the output signal. Referring to Figure 2, we can see how this is done. For a moment let us again assume that the circuit is operating with diodes 18 i and 18 i+1 supplying the signals generating the output signal V Out. The output of 18 i is produced on lines 20, fed through device 34,and gain amplifier 36 and into the summing amplifier 38 while the output of device 18 i+1 is put on line 22, passed through conductive device 40, and amplffier-42 and fed to the other input of the summing amplifier 38 to thereby produce the output signal V Out.
- the output signals are also differentially summed in differential amplifiers 44 and 46.
- differential amplifier 44 the signal coming through amplifier 36 is positive in the summation while in the differential amplifier 46 the signal coming through amplifier 42 is positive in the summation.
- the differential sum outputs are fed to trigger circuits 48 and 50.
- the threshold level for these trigger circuits is set at a point equal to or slightly less than the maximum output points 32 in the operating curves of the two diodes 18 i and 18 i+1 Therefore, so long as the light is directed between the two diodes 18 i and 18 i+1 , there will be no pulse produced by the trigger circuits 48 or 50 and the outputs on lines 20 and 22 are the signals from diodes 18 i and 18 i+1 respectively.
- trigger circuit 48 will produce a pulse.
- trigger circuit 50 will produce a pulse. These pulses will be used to generate decode signals that will shift the two up voltages on gate lines i and i+1 one line in either direction.
- the AND gates 52, 54, 56 and 58 and flip flop circuit 60 generate those decode signals.
- the output of both trigger, circuits 48 and 50 are coupled to the trigger input of flip flop 60.
- the output of trigger circuit 48 is fed to one terminal of two input AND gates 52 and 54, and the output of trigger circuit 50 is fed to one terminal of AND gates 56 and 58.
- the other terminal of AND gates 54 and 58 is the Q output of the flip flop 60 and the other input to the AND gates 52 and 56 are the Q output of the flip flop 60.
- This pulse disconnects either diode 18 i from line 20 or diode 18 i+1 from line 22 and connects either diode 18i+2 to line 20 or diode 18 i-1 to line 22 resulting in the shift of the conducting diodes one diode position in either direction along the diode string. This will be discussed in more detail with references to Figure 3.
- the outputs Q and Q also control whether the signal on line 20 is fed to amplifier 36 or 42 and whether the signal on line 22 is fed to amplifier 36 or 42.
- the flip flop 60 is in its Q state while diodes 18 i and 18 i+1 are conducting and the track position shifts sufficiently to cause trigger circuit 48 to produce a pulse.
- This pulse will be fed to the trigger terminal of flip flop 60 switching the flip flop from its Q state to its Q state.
- devices 64 and 66 will be rendered conductive and devices 34 and 40 will be rendered non-conductive. The effect of this is to couple diode 18 i+1 to the amplifier 36 and diode 18 i-1 to the amplifier 42.
- the signals generated by AND gates 52 through 58 control the count on two counters.
- the output of AND gate 52 is coupled to the increment input to the counter 64 and the output of AND gate 58 is coupled to the decrement input to the counter 64 associated with the lower line 22.
- the counter 64 is a six bit up/down counter. The production of a pulse by AND gate 52 will increase the count in the counter by one and production of the pulse by AND gate 58 will decrease the count in the counter by one. The true and complements of the three low order bits of counter 64 are generated and fed to the inputs of eight separate 3 to 8 decoders 68.
- the true and complement of the three high order bits of the counter 64 are fed to the inputs of another 3 to 8 decoder 70.
- Each of the eight outputs of the decoder 70 is a gating signal for one of the decoders 68 so that with each count . of the counter, the decoder 70 selects and activates one and only one of the decoders 68 using the high order digits of counter 64 and then the low order bits of the counter are used to place a positive voltage on one and only one output of the activated decoder 68.
- Each'of the eight outputs from the decoder 68 is connected to control a different one of the devices 24, so that a different one of the 64 diodes 18 is connected to the line 22 with each count.
- the decode circuitry associated with the upper line 20 is identical to those controlling the connections to the lower line, with the exception that the AND gate 54 drives the increment input and AND gate 56 drives the decrement input to the counter associated with the upper line 20.
- FIGURE 1 shows how the summed output V i + V i+l does not vary much in amplitude over the range between adjacent peaks 32.
- FIGURE 4 shows a layout of a diode 18 and its associated connections for the lower half of the sensor.
- the layout for a diode 18 in the upper half of the sensor is.the mirror image of the layout shown here.
- a substrate of 'P' type material contains a number of 'N' type diffusions.
- the diffusion 74 contains an enlarged portion 74a which functions as the cathode of the diode 18.
- the other end of the diffusion 74 is the source of the FET 24 coupling the diode to the line 22.
- the narrow end 76 of a diffusion 76 forms a the drain of the FET 24.
- a metalisation pattern 88 overlying the diffusions 74 and 76 on an insulating layer forms the gate for the device and the coupling to the gate decode logic 68.
- a second metalisation pattern 80 on the insulating layer forms the line 22.
- the line 22 is connected to the drain of the FET 24 by a metal connection 86 through the insulating layer.
- a third metalisation pattern 82 forms a line which overlies and is connected to a diffusion 84 by a metal connection 90 through the insulating layer to form a FET for voltage clamping purposes.
- a second insulating layer covers all of the chip and it is . covered by a second metalisation layer which covers the whole chip except the diodes 18 at 72 to shield the circuitry from light. 72 indicates a window for light to all the diodes 18 and also the position of a diffusion layer constituting a common anode for all the diodes.
- the 128 diodes 18 of the sensor are driven by mechanical means to move radially across the face of the disc:to be in the region where the light from 14 is being reflected.
- a longer stationary string of diodes 18 could be used to read the whole disc without movement and avoid the use of a drive mechanism.
- the track provided a more intense reflection than the surrounding guide bands. The present invention would work equally as well if the opposite were true.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Optics & Photonics (AREA)
- Electromagnetism (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Optical Recording Or Reproduction (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
- Burglar Alarm Systems (AREA)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT80301240T ATE6553T1 (de) | 1979-04-18 | 1980-04-17 | Spurverfolgungsanordnung fuer einen sensor zur wiedergewinnung von auf eine informationsspur aufgezeichneten signalen. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US3125279A | 1979-04-18 | 1979-04-18 | |
US31252 | 1979-04-18 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0018211A1 true EP0018211A1 (de) | 1980-10-29 |
EP0018211B1 EP0018211B1 (de) | 1984-03-07 |
Family
ID=21858415
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP80301240A Expired EP0018211B1 (de) | 1979-04-18 | 1980-04-17 | Spurverfolgungsanordnung für einen Sensor zur Wiedergewinnung von auf eine Informationsspur aufgezeichneten Signalen |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0018211B1 (de) |
JP (1) | JPS55142424A (de) |
AT (1) | ATE6553T1 (de) |
CA (1) | CA1145463A (de) |
DE (1) | DE3066800D1 (de) |
HK (1) | HK50286A (de) |
MY (1) | MY8700048A (de) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2514913A1 (fr) * | 1981-10-16 | 1983-04-22 | Cii Honeywell Bull | Dispositif opto-electronique de lecture d'informations contenues sur un support magnetique |
US4695991A (en) * | 1980-12-09 | 1987-09-22 | Storage Research Pty. Ltd. | Reading information stored in multiple frame format |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3158846A (en) * | 1961-01-23 | 1964-11-24 | Silverman Daniel | Information retrieval systems |
DE2033557A1 (de) * | 1970-07-07 | 1972-01-20 | Licentia Gmbh | System zur Speicherung und Wieder gäbe von Daten |
US3739154A (en) * | 1972-05-01 | 1973-06-12 | Ampex | Optical tracking apparatus for read out of high density recording |
US3769465A (en) * | 1969-08-18 | 1973-10-30 | Ibm | Electronic servo in magnetic recording readout |
US3780266A (en) * | 1971-02-25 | 1973-12-18 | Licentia Gmbh | Apparatus for scanning signals |
DE2337494A1 (de) * | 1973-07-24 | 1975-02-13 | Licentia Gmbh | Anordnung zur abtastung von signalen laengs mindestens einer spur |
BE831264A (fr) * | 1975-07-11 | 1975-11-03 | Systeme de lecture d'informations sur disque | |
US3931459A (en) * | 1974-02-04 | 1976-01-06 | Zenith Radio Corporation | Video disc |
FR2312091A1 (fr) * | 1975-05-21 | 1976-12-17 | Philips Nv | Systeme optique de memorisation sur disque a canaux multiples pour la mise en memoire d'informations numeriques |
US4047022A (en) * | 1976-01-13 | 1977-09-06 | Ernst Leitz Gmbh | Auto focus with spatial filtering and pairwise interrogation of photoelectric diodes |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3934130A (en) * | 1974-08-22 | 1976-01-20 | General Electric Company | Digital differential analyzer |
JPS5128720A (de) * | 1974-09-04 | 1976-03-11 | Mitsubishi Electric Corp |
-
1980
- 1980-03-06 JP JP2746280A patent/JPS55142424A/ja active Granted
- 1980-03-17 CA CA000347801A patent/CA1145463A/en not_active Expired
- 1980-04-17 AT AT80301240T patent/ATE6553T1/de not_active IP Right Cessation
- 1980-04-17 EP EP80301240A patent/EP0018211B1/de not_active Expired
- 1980-04-17 DE DE8080301240T patent/DE3066800D1/de not_active Expired
-
1986
- 1986-07-03 HK HK502/86A patent/HK50286A/xx unknown
-
1987
- 1987-12-30 MY MY48/87A patent/MY8700048A/xx unknown
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3158846A (en) * | 1961-01-23 | 1964-11-24 | Silverman Daniel | Information retrieval systems |
US3769465A (en) * | 1969-08-18 | 1973-10-30 | Ibm | Electronic servo in magnetic recording readout |
DE2033557A1 (de) * | 1970-07-07 | 1972-01-20 | Licentia Gmbh | System zur Speicherung und Wieder gäbe von Daten |
US3780266A (en) * | 1971-02-25 | 1973-12-18 | Licentia Gmbh | Apparatus for scanning signals |
US3739154A (en) * | 1972-05-01 | 1973-06-12 | Ampex | Optical tracking apparatus for read out of high density recording |
DE2337494A1 (de) * | 1973-07-24 | 1975-02-13 | Licentia Gmbh | Anordnung zur abtastung von signalen laengs mindestens einer spur |
US3931459A (en) * | 1974-02-04 | 1976-01-06 | Zenith Radio Corporation | Video disc |
FR2312091A1 (fr) * | 1975-05-21 | 1976-12-17 | Philips Nv | Systeme optique de memorisation sur disque a canaux multiples pour la mise en memoire d'informations numeriques |
BE831264A (fr) * | 1975-07-11 | 1975-11-03 | Systeme de lecture d'informations sur disque | |
US4047022A (en) * | 1976-01-13 | 1977-09-06 | Ernst Leitz Gmbh | Auto focus with spatial filtering and pairwise interrogation of photoelectric diodes |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4695991A (en) * | 1980-12-09 | 1987-09-22 | Storage Research Pty. Ltd. | Reading information stored in multiple frame format |
US4947383A (en) * | 1980-12-09 | 1990-08-07 | Hudson Allen Limited | Machine readable markers for cartesian information storage media |
FR2514913A1 (fr) * | 1981-10-16 | 1983-04-22 | Cii Honeywell Bull | Dispositif opto-electronique de lecture d'informations contenues sur un support magnetique |
EP0077693A1 (de) * | 1981-10-16 | 1983-04-27 | Bull S.A. | Opto-elektronische Vorrichtung zum Auslesen der Information eines magnetischen Aufzeichnungsträgers |
Also Published As
Publication number | Publication date |
---|---|
JPS6214890B2 (de) | 1987-04-04 |
ATE6553T1 (de) | 1984-03-15 |
JPS55142424A (en) | 1980-11-07 |
CA1145463A (en) | 1983-04-26 |
HK50286A (en) | 1986-07-11 |
DE3066800D1 (en) | 1984-04-12 |
MY8700048A (en) | 1987-12-31 |
EP0018211B1 (de) | 1984-03-07 |
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